Table of Contents  Linear Actuator  Base  Arm/Elbow Joint  Future Plan

 Previous Issues: Rack and gear meshing slop Uniform linear movement through bearings Drive motor needs replacement  Improvement Ideas: Mount second gear to face of primary gear Replace linear roller bearings with sleeve bushings Replace motor with higher torque version Linear Actuator

Fasten new gear to primary gear to increase contact area of gear to linear rack Chose sleeve bushing to increase surface contact on rack to increase stability Will reduce twisting and bending slop Eliminate linear ball bearing for smoother motion

Current motor is inopperable 256:1 Motor ordered to replace the 64:1 motor previously in place. Higher Torque, but lower speed

Base Setup

POT Drive Gear Current Base Setup ~1/8” slop from lazy susan

Drive Gear New Base Setup

Direct Drive Motor Base Plate Connection Drive Bearing Moving part of motor

Arm/Elbow Problems  1/8in arms Arm twists too much Not rigid enough assembly  Elbow helical gears Creates lateral loads on arm Low gear ratio results in small torque increases Exposed gearing picks up debris

Quick Fix Ideas  Channel Arm Idea Lighter, strong, resists torsion, but hard to make  Square Tube Idea Heavier, strong, and easier to make

New Arm 1 st iteration

Progress so far

Test Assembly: Chipping Rock Goal: Replace the linear actuator with a more powerful assembly to break rock.

Future Milestones  1 st Iteration redesign – Nov. 28th th  Interim Report Fall Semester – Dec. 9 th  Final Design Decision – Dec  Senior Design Expo – May 2008